7. A sample of gas has a volume of 15.0 L when at a temperature of 220 K and a pressure of 310kPa. (Ideal gas Law)
a. 4a. Find the number of moles of gas.
b.
4b. If there are 52 g of the gas in the sample, which noble gas is it?

What is a scientific theory? a. a scientist's guess about how something works b. the results of an experiment obtained using the scientific method c. a proven fact that will never change d. an idea that is backed by data from many sources

What are the spectator ions in 2h+ + so42- + ca2+ + 2r → caso4 + 2h+ + 21?

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.